Possible Infertility

My fiancé and I  have decided to officially start trying for a baby! I've been off birth control for 2 years now. We first tried when I first got off with no luck. I'm starting to feel concerned and scared to start trying because I feel as if one of us may be infertile. Is there any symptom or way to tell if you're infertile? Any tips to help increase our odds of conceiving? Also, we both are around 20 so age isn't a factor.